In recent years, as AV (Audio/Visual) apparatuses using digital signals, such as audio signals and video signals, have been broadly used, various methods have been proposed as interfaces for transmitting digital signals among the AV apparatuses. As such an interface, an IEEE (Institute of Electrical and Electronics Engineers) 1394 standard and an HDMI (High-Definition Multimedia Interface) standard (HDMI is a registered trademark), for example, are generally known (refer to Patent Document 1, for example.)
When AV apparatuses are connected to each other using such an interface, it is assumed that video images are displayed using a television receiver apparatus and sound is output from an AV amplifier. In this case, since video processing time of the television receiver apparatus and audio processing time of the AV amplifier are different from each other, there arises a problem in that time lag occurs between a video image and sound. To address this problem, a system, for example, which attains synchronization (lip sync) between a reproduced video image and reproduced sound by supplying processing time for video-image processing in accordance with the HDMI standard from the television receiver apparatus to the AV amplifier so that processing of audio signals is delayed has been proposed (refer to Patent Document 2, for example).
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2007-267116 (FIG. 1)
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2006-033436 (FIG. 1)